Airsoft guns are replica weapons that fire spherical non-metallic pellets rather than the lethal ammunition that the replica weapons are based upon. Airsoft also refers to a sport played with these airsoft guns that is similar to paintball, except that the pellets fired by the airsoft guns do not leave a color mark like that left by a paintball, and the participants typically play on the honor system of acknowledging when being hit by a pellet from an opponent's airsoft gun. Along with reduced mess, airsoft guns are typically cheaper to acquire and operate than paintball guns, and can also be used more easily for casual target practice when not engaged in competition. Airsoft guns employ compressed air to fire round these plastic pellets or similar projectiles, usually ranging from 0.12 g to 0.48 g.
Various “firing” mechanisms are known in the art for airsoft guns. For instance, U.S. Pat. No. 7,527,049, issued to Sheng, discloses a pneumatic pusher having a main body, a flow-guiding body, a moving body, and a delivery tube. The flow-guiding body includes a front tube with a smaller diameter and a rear tube with a larger diameter. The delivery tube is mounted on the front tube in such a way that the outer wall of the delivery tube and the inner wall of the main body define a return pressure chamber. A first gas-distributing channel extending from a first air outlet at one side of the main body leads directly to the inner side of the delivery tube. The side of the first air inlet of the main body communicates with a second gas-distributing channel. The second gas-distributing channel includes an exit located at one side of the return pressure chamber of the delivery tube. The air pressure provided through the second gas-distributing channel serves as cushioning force in pushing the delivery tube outwardly.
U.S. Pat. No. 8,453,633, issued to Tsai, discloses a spring-piston airsoft gun that includes a cylinder-and-piston assembly disposed in a barrel to force air through a muzzle end to make a shooting action, and a coil spring disposed to exert a biasing action to drive a piston head of the cylinder-and-piston assembly when changed from a compressed state to a released state. Front and rear anchor shanks are disposed for respectively mounting front and rear coil segments of the coil spring. A major shell and a minor ring are sleeved on the rear anchor shank to permit the coil spring to be sleeved thereon. The minor ring is in frictional contact with and angularly moveable relative to the major shell such that, when the coil spring is released to expand to the released state, the rear coil segment is tensed to drag the minor ring to angularly move therewith so as to minimize the frictional force therebetween.
U.S. Pat. No. 8,671,928, issued to Hague et al. and assigned to Polarstar Engineering & Machine, discloses a pneumatic assembly for a projectile launching system includes a body defining a continuous bore. A nozzle is positioned within the bore adjacent a forward end and is moveable between a rearward position wherein the nozzle facilitates passage of a projectile through a projectile port and a forward position wherein the nozzle prevents passage of a projectile through the projectile port. The nozzle is biased to the forward position and configured for fluid actuation to the rearward position by activation of a first fluid control valve. A valve seat defines an accumulation chamber rearward of the nozzle. A firing valve member is moveable between a forward position wherein the firing valve member fluidly seals a passage through the valve seat and a rearward position wherein the passage is fluidly opened such that fluid in the accumulation chamber is free to flow through the passage and out of the nozzle. Example embodiments of this pneumatic assembly generally include a nozzle spring contained between the rear surface of the nozzle and the front surface of a center cylinder.
U.S. Patent Application Publication Number 2012/0216786, by Hadley and Calvin, teaches a soft impact projectile launcher including a launching mechanism that creates a burst of air or air pressure in order to launch a projectile. The launching mechanism includes an outer cylinder and a spring-loaded piston configured to generate the burst of air. The projectile launcher may also include a projectile reservoir and a loading member that positions projectiles for launching. The projectile launcher can launch projectiles that are made from a superabsorbent polymer and consist of mostly water.
U.S. Patent Application Publication Number 2013/0247893, by Yang, teaches an airsoft gun structure designed to shunt high-pressure air flow during shooting. Therefore, the shunted high-pressure air flow simulates recoils as real bolt-action, single-shot rifles. Also, the ammunition supply includes different cartridges to select one of the supply-type by the users and whether shell case ejection or not. When operates the airsoft gun, the realistic action is achieved to enhance the fun of shooting. Furthermore, the dual hop up system makes the flight path of bullets more stable without shift. Moreover, the safety gasification system could make the supplied amount of the output compressed high pressure air be almost constant to enhance security during operation. The devices disclosed in Yang include a hammer block spring or magazine spring attached to an inner surface of the back block in an inner barrel.
One of the most valued aspects of airsoft guns is the authentic look of the guns, as the appearance closely adheres to the actual weapons upon which they are replicated. Unfortunately, airsoft rifles, such as M4 style airsoft rifles, typically require the user to wear a compressed air tank to supply compressed air to the airsoft rifle. Thus, the typical user not only suffers the inconvenience of wearing the compressed air tank, but also the unsightly appearance of an air hose leading from the tank to the airsoft rifle. These two complaints are often the reasons cited by potential users of airsoft, or High Pressure Air (HPA), technology that remain resistant to entering the field. Thus, there exists a desire to improve the appearance and functionality of airsoft rifles to eliminate the need for external compressed air tanks.